Generally, a slide rail assembly (or slide rail) in a rack-based system is mounted on two posts of a rack via two brackets respectively. An object, therefore, can be mounted to the rack through the slide rail assembly. The slide rail assembly also allows the object to stay in the rack and be pulled out of the rack whenever necessary. U.S. Pat. No. 9,370,120 B2, for example, discloses a slide assembly for installing a chassis to a rack. This slide assembly at least includes an engaging member pivotally connected to the bracket board of a bracket. The engaging member includes a body portion, a first fastening portion, and a second fastening portion, wherein the second fastening portion is configured to form an engaging space with respect to the first fastening portion. The at least one hook portion of the chassis can be inserted into the engaging space of the engaging member from below to contact against the second fastening portion, thereby preventing the chassis from being pulled out of the rack by a random attempt. The disclosure of this US patent is incorporated herein by reference.